I can't run drush in my current project. The error I keep getting is:
[preflight] A colon cannot be used in an unquoted mapping value at line 3 (near " in Command line code on line 1").
This is a Drupal 8 project I've recently updated and I'm about to migrate to Drupal 9. I'm running Drush 10.3.1
I've deleted and reinstalled drush,
I'm guessing "Command" should point me to something but I can't figure out what. Any ideas on how to troubleshoot this?